Antalis

Abstract: Cystophorous cercariae developing in rediae in Antalis entalis (L.) (Syn.: Dentalium entale ) (Mollusca, Scaphopoda) were found in Norwegian waters off Bergen. The second intermediate (crustacean) hosts are unknown. Experimental infections of copepods and various malacostracans with the immotile cystophorous cercariae were unsuccessful. In one instance, three cercariae developed into metacercariae in one specimen of Antalis entalis kept in an aquarium for 11 months. The cercaria and redia are described using light microscopy and scanning electron microscopy. Serial sections of rediae revealed a vestigial pharynx and caecum. The cercaria is compared with other cystophorous cercariae from scaphopods and other molluscs. The redia and cercaria differ slightly from those of Cercaria prenanti Arvy, 1949 in Antalis entalis from France, but are very similar to Cercaria prenanti from the American Pacific. The metacercaria is very similar to young specimens of Lecithophyllum botryophorum (Olsson, 1868) Odhner, 1905...

Abstract: An assemblage of scaphopods, the richest in Poland, occurs in the Lower Tortonian Pleurotoma clays outcropped in the environs of Korytnica on southern slopes of the Holy Cross Mts. All in all, this assemblage includes thirteen species, that is, four hitherto known from this locality and nine others, four of which are here described as new ones. This is one of the richest assemblages of these molluscs in the Miocene of Europe and in the number of species yields only to some Miocene localities of Italy. Dentalium (Antalis) fossile Schroeter and Fustiaria ( Episiphon ) miocaenica (Boettger) are most frequent species at Korytnica. The present paper contains paleontological descriptions of particular species, along with characteristics of their life environment. This assemblage has also been compared with those from other Miocene localities and a considerable similarity has been found to the scaphopods of the Vienna Basin, of the environs of Pleven, Bulgaria, and of the environs of Kostej, Transylvania.

Abstract: The development and microanatomy of the protonephridial system in larvae and postmetamorphic juveniles of Antalis entalis (Dentaliidae) have been examined by means of a semithin serial sectioning and reconstruction technique. One late larval stage has been additionally examined by transmission electron microscopy. The protonephridium appears during larval development and is reduced in the juvenile approximately 13 days after metamorphosis. This is the first unambiguous evidence of a protonephridium in a postlarval mollusc. When fully developed the protonephridium is unique in consisting of two cells only, a terminal cell (=cyrtocyte) and a duct-releasing cell with glandular appearance. The polyciliary terminal cell has several distinct ultrafiltration sites, resembling conditions in bivalve protonephridia. The large duct-releasing cell shows a very large nucleus probably reflecting polyploidy. Its basal infoldings and many mitochondria suggest metabolic activity, the cytoplasm is characterised by many distinct granules. The unique features of the scaphopod protonephridial system are compared with available data on the protonephridia of other molluscan classes. The finding gives additional evidence that protonephridia belong to the ground pattern of the Mollusca.

Abstract: An examination of benthic material collected from different depths (0-875 m) and habitats along the Turkish Levantine and Aegean seas between 1996 and 2008 has resulted in the identification of 819 scaphopod specimens, belonging to 10 species: Antalis dentalis (Linneaus, 1758), Antalis inaequicostata (Dautzenberg, 1891), Antalis panorma (Chenu, 1843), Antalis rossati (Caprotti, 1966), Antalis vulgaris (da Costa, 1778), Fustiaria rubescens (Deshayes, 1825), Entalina tetragona (Brocchi, 1814), Pulsellum lofotense (M. Sars, 1865), Cadulus jeffreysi (Monterosato, 1875), and Dischides politus (S. Wood, 1842). Of these, P. lofotense and C. jeffreysi are new records for the Aegean molluscan fauna and A. panorma and F. rubescens are new to the Levantine coast of Turkey. Of the identified species, A. inaequicostata was the most widely distributed along the Turkish coast, whereas C. jeffreysi was the rarest, and was encountered in only 2 places. Entalina tetragona was significant as the deepest living species, sampled from depths between 96 and 875 m. Some ecological characteristics and taxonomic remarks, with colour photographs of the identified species, are provided.